// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_I18N_BIDI_LINE_ITERATOR_H_
#define BASE_I18N_BIDI_LINE_ITERATOR_H_

#include "base/i18n/base_i18n_export.h"
#include "base/i18n/rtl.h"
#include "base/macros.h"
#include "base/strings/string16.h"
#include "third_party/icu/source/common/unicode/ubidi.h"

namespace base {
namespace i18n {

    // A simple wrapper class for the bidirectional iterator of ICU.
    // This class uses the bidirectional iterator of ICU to split a line of
    // bidirectional texts into visual runs in its display order.
    class BASE_I18N_EXPORT BiDiLineIterator {
    public:
        BiDiLineIterator();
        ~BiDiLineIterator();

        // Initializes the bidirectional iterator with the specified text.  Returns
        // whether initialization succeeded.
        bool Open(const string16& text, TextDirection direction);

        // Returns the number of visual runs in the text, or zero on error.
        int CountRuns();

        // Gets the logical offset, length, and direction of the specified visual run.
        UBiDiDirection GetVisualRun(int index, int* start, int* length);

        // Given a start position, figure out where the run ends (and the BiDiLevel).
        void GetLogicalRun(int start, int* end, UBiDiLevel* level);

    private:
        UBiDi* bidi_;

        DISALLOW_COPY_AND_ASSIGN(BiDiLineIterator);
    };

} // namespace i18n
} // namespace base

#endif // BASE_I18N_BIDI_LINE_ITERATOR_H_
